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油田作业队野外作业安全照明系统研究与开发 总被引：1，自引：0，他引：1
详细讨论了作业队夜间、作业现场在照明中存在的问题,改进思路,分析了24V低压 车载防爆照明系统的研发优势,并对前景进行预测。 相似文献
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浅谈毕业设计对加强学生工程实践能力的作用 总被引：4，自引：1，他引：4
杨子鸣 《电气电子教学学报》2004,26(1):110-112
本文主要介绍在毕业设计中,如何转变指导方法,改革毕业实习环节,不断更新工程设计思路。加强对学生工程实践能力和创新精神的培养,使设计成果能贴近工程实际,能反映出科学技术的发展和时代气息,并考虑工程设计应体现经济效益最大化的思路。特别是在指导供配电毕业设计中,对应用“总拥有费用法TQC”评价变压器;采用IEC标准的截面经济最优化计算方法来选择电力电缆等方面作出了一些探讨。 相似文献
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介绍了一种野外作业移动库房安防系统的设计和实现方案。该系统以C8051F120单片机为主控制器,以STC89C52单片机为从控制器,以热释电红外感测器D203S为核心构成人体检测模块,以烟雾传感器MQ-2为核心构成烟雾检测模块,采用CRM2400TNC无线模块实现主、从控制器之间的通信,可实现库房内人员监测、烟雾检测以及库房物品进出情况监测及报警功能,且只有输入正确的密码才能关闭报警系统。测试结果验证了该系统的有效性和可靠性。 相似文献
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Anna Marshall;Ryan R. Morrison;Brady Jones;Shayla Triantafillou;Ellen Wohl; 《河流研究与利用》2024,40(3):353-364
Wood accumulations influence geomorphic, hydraulic, and ecologic functions within a river corridor, but characterizing these accumulations presents challenges across a range of field and remote sensing methodologies. We evaluate the ability of handheld lidar scanners, specifically lidar-scanning capabilities of a fourth-generation iPad Pro, to collect three-dimensional wood accumulation data, which can be used to inform measurements of wood volume, porosity, complexity, and roughness. We discuss the potential and limitations of this novel methodology for river research and management. We found that handheld lidar presents a cost-effective input for data-processing workflows that field measurements of wood accumulation dimensions cannot as easily replicate including (1) a user-friendly means of data collection and visualization; (2) accurate comparisons of wood volume over time; (3) integration into workflows to measure porosity parameters; and (4) potential use in informing hydraulic and morphodynamic models. Consideration of study area constraints and intended use of scans are prerequisites to using handheld lidar as an effective tool. We identified some specific limitations of using handheld lidar scanners in wood-rich river corridors, including (1) scanners perform poorly when wood is under water or surrounded by dense vegetation; (2) scanners require physical access to areas of interest at distances less than 5 m; (3) scans need to be manually georeferenced; and (4) scans require manual measurements for any dimensional data, which still have associated user time and error. Handheld lidar as a scientific tool is rapidly developing and there is substantial room for expansion of applications, utilization, and advances in the use of this tool in river research and management. 相似文献
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The concept of ‘the field’ is significant in ethnographic research as well as qualitative research methods more generally. However, how a field researcher enters the field is usually taken for granted after gaining access to the field. We suggest that entrance is a distinct phase of fieldwork that differs from negotiating access. Entrance is not a trivial event; rather, it is a rite of passage into a complex practice world and marks a critical field moment. Drawing on our ethnography and insights from hermeneutics and anthropology, we show that a practical understanding of the field represents a fusion of horizons where a fieldworker is thrown. The concept of thrownness highlights the fact that the fieldworkers' own historicity and prejudices affect their entrance into the field; hence, entrance into the field orientates an ethnographer in the field and influences the entire period of fieldwork that follows. Our theorizing is intended as a contribution towards advancing the discussion of qualitative research methods. 相似文献
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结合刘祖云教授所著的《江苏乡村治理发展报告》,从方法论视角全面解读中国乡村治理的研究概貌。在研究定位上,经历从"村落"到"乡域"的拓展;在研究范式上,超越"村落社区"的观察视角不断被探索;在研究方法上,主要采用"田野调查"与"个案深描";在研究理路上,主要遵循"个别到一般"逻辑脉络;在研究走向上,应努力建立起中国乡村治理研究的本土化理论体系。 相似文献
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胶东半岛凭借三面环海的地理区位,成为道家思想的重要发源地。金元时期,内丹派全真道于此创立,使该地山岳道家文化景观得以迅速发展。在半岛特殊的自然气象、资源、地貌条件影响下,山岳道家文化景观的营造呈现出\"序列性\"特征,且其物象与内丹修道理论密切相关,形成诸多\"山地风景道\"。通过田野调查、测绘、访谈,探讨该类\"风景道\"的环境基底特征和文化内涵,总结\"风景道\"的景观层次与要素组成,并对其空间特征与要素布局进行分析。研究发掘了胶东半岛山岳道家文化景观的潜在规律,为保护当地该类景观提供新的视角,亦可为其他地域该类景观保护提供借鉴。 相似文献